(1) Field of the Invention
This invention relates to a teaching-playback type automatically running vehicle which first memorizes, during travel under manual control, the steering angle patterns of the vehicle wheels while the vehicle traverses a given distance along a course from the starting point. During subsequent passages along the course, the vehicle may be automatically run by self-manipulation of the steering angle of the vehicle wheels in accordance with the memorized pattern.
(2) Description of the Prior Art
Among the conventional unmanned automatically running vehicles there is for instance a type which automatically follows a track or guide line disposed over the entire course. Such a system has the disadvantage that in the case of a long distance course, the installation cost of the track or guide line is too high, and because of such costly installation, the course cannot easily be modified or altered after the specific course pattern has been installed. Also, installation of such a track or guide line may cause hindrance to other vehicles which may be operated along portions of the course, such as work vehicles and lawn mowers or the like. It is thus practically impossible to have an automatic running vehicle perform automatic travel by means of a track or guide installed over the entire course.
There has recently been proposed an unmanned automatically running vehicle of the teaching-playback type. Such a teaching-playback vehicle is preferred to the said guide line type in view of the fact that the teaching-playback vehicle can follow any arbitrary course pattern once the pattern is memorized. However, since a teaching-playback vehicle performs in accordance with the memorized data along, any possible initial error in the placement or orientation of the unmanned automatically running vehicle and/or errors introduced during the running of the vehicle (resulting from external disturbances such as irregular ground undulations wind forces or the like), will never be remedied but will become progressively larger and larger as the vehicle runs on and on. Improvements have therefore been desired in this regard.